This invention relates to detergent compositions having superior detergent and fabric softening properties. In the fabric softening art, it is well known to prepare fabric softening formulations which are adapted for use in the rinse cycle of conventional home-laundry washing machines. As a general rule, any one of a wide variety of softening agents may be used, and they are normally formulated as dispersions in water containing from about 4% to about 7% of the active ingredients.
It has been recognized for some time that it would be desirable as a matter of convenience to employ the fabric softening formulation concurrently with the detergent in the wash cycle of the washing machine. In many of the home laundry washing machines now in use, the machine is so designed that in order to use a rinse cycle fabric softener it is necessary for the housewife to watch the cycle carefully, and to interrupt the cycle just before the final washing step to add the fabric softening agent, because no special provision has been made for dispensing fabric softeners at the time of the final rinse. The use of fabric softeners in such machines manifestly would be made considerably more convenient if it were possible for the housewife to add the fabric softener together with the laundry detergent, whereby the softener would act concurrently with the detergent simultaneously to wash and to soften the fabrics.
Conventional fabric softening formulations can be used as wash-cycle softeners. However, in order to obtain a reasonable amount of softening it is necessary to use generally in the order of twice the normal amount of formulation. Because this would require the housewife to maintain large quantities of fabric softening formulations on her shelves, and would involve an apparently wasteful use of fabric softeners, housewives are reluctant to employ the fabric softening formulations currently available as washcycle softeners.
To overcome this difficulty, it would be desirable to provide a concentrated composition containing both detergent and fabric softener which, when used in a small quantity, would provide effective cleaning and softening of fabrics in the home laundry machine. For this purpose, a formulation having a very high concentration of active ingredients would be needed. It has not been possible heretofore to prepare one-phase liquid compositions employing the commercially accepted fabric softeners and detergents available. The generally effective fabric softeners which have found widespread commercial acceptance, such as the di-(higher alkyl)-di-(lower alkyl) ammonium salts, cannot be formulated into one-phase liquid compositions which are stable at high concentrations. Using the typical commercially available fabric softening agents, formulations containing a maximum of 7% to 8% active ingredient can be prepared without incurring stability difficulties.